This application describes the extension of single-electron transistors (SET's) to biochemical detection. Theses devices are sensitive to even single-molecular binding events and use very little power. Fabricated with standard silicon micromachining techniques, they are rapidly and inexpensively produced, and easily adaptable to specific application requirements. This project will demonstrate their use in monitoring the coupling of biotin/steptavidin, as well as DNA oligomer hybridization in order to demonstrate the effectiveness of SET's for biological research (microarrays), medical diagnostics, and biochemical warfare defense. PROPOSED COMMERCIAL APPLICATION: This device will have commercial potential in the areas of point-of-care medical diagnostics, biological research, genomics, and biochemical warfare defense.